Dr. Julie, a.k.a. Scientific Chick, brings you insights into what's happening in the world of life sciences. Straight from the scientific source, relevant information you should know about, in plain language.

Sunday, September 26, 2010

The traveling exhibit Body Worlds & the Brain has arrived in Vancouver. For those of you who are not familiar with Body Worlds, it is an exhibit that features real human bodies and human body parts that have been preserved through a process called plastination. Through my new line of work at the National Core for Neuroethics, I've become involved with Science World, the organization hosting the exhibit in Vancouver. And because of this involvement, I have now seen the exhibit for the first time. Here are my thoughts about Body Worlds, and I would be most interested to hear yours, whether you've seen it or not.

Before seeing the exhibit, I wasn't very warm at the idea. I had read a lot of ethics articles questioning whether the exhibit preserved human dignity, and whether human bodies could be considered art. The thought of those preserved bodies, with their eyes staring at me, definitely gave me the creeps. I was concerned with issues like consent, and I was uneasy with the fact that the whole thing felt like a freak show, a very profitable freak show.

I was lucky to see the exhibit on a special opening night for volunteers. On the plus side, it wasn't very busy, and I got to scrutinize everything. On the down side, this meant I had to listen to endless speeches before entering the exhibit.

It's during one of these speeches that my gut feeling about Body Worlds completely turned around (keep in mind, by then I still haven't seen any part of the actual exhibit). One of the speakers discussed how powerful it is to witness the complexity and fragility of the human body, and how this can lead to profound changes in how we view ourselves, and how we take care of ourselves. The speaker was very convincing. Seeing as I'm concerned with caring for my body and tremendously interested in science communication, I started thinking that perhaps I was wrong, and perhaps the "good" of the exhibit (teaching people about the fragility of their bodies) far outweighed the "bad" (ethical questions about dignity and such).

Then I finally got to enter the exhibit and decide for myself, and a really funny thing happened: nothing. I didn't feel any strong negative emotions, didn't think it was gross, inappropriate, or disturbing. But I also didn't feel any strong positive emotions either: didn't think it was cool, beautiful, or awe-inspiring. I mostly didn't care, and frankly I was quite bored by the end of it all.

I'm not quite sure what to make of this as I was very much expecting to feel something. Part of the reason for my lack of interest could have been that the shock factor was lost on me. After several years of dissecting rodents, I've seen my fair share of guts and brains, albeit on a smaller scale. Perhaps I had over-thought the whole thing too much prior to seeing it. I'm not sure.

I would love to read your thoughts about this. Have you heard of Body Worlds? Were you motivated to go see it? What was your gut instinct if you did see it? What did you learn? If you chose not to see it, why?Share in the comments!

Sunday, September 19, 2010

We hear a whole lot about new brain imaging techniques lately. It seems like imaging studies are constantly revealing new pieces of information about the brain: what part of the brain is responsible for our morality, what happens when you fall in love, and so on. One of the main techniques used in these studies is called functional magnetic resonance imaging (fMRI). Unlike a regular MRI, which takes a static image, fMRI can give us images of a dynamic process: the flow of oxygenated blood in the brain. Presumably, when one region of your brain is activated, the brain cells require more oxygen, so more oxygenated blood flows to that region, and this can be seen and measured using fMRI.

While it may be very interesting to find out what happens to your brain when you fall in love, we have yet to see real clinical benefits from these fancy new brain scans. Brain disorders and diseases, such as depression and Alzheimer’s disease, still cannot be diagnosed using fMRI. One of the reasons for this limitation is that an fMRI scan for a single person really doesn’t tell us much: we can only gain insights from this technique if we look at groups of people, and compare averages. To this day, this problem has really limited the potential of fMRI for diagnosing brain diseases. However, a recent publication in the journal Science suggests that fMRI may soon be clinically relevant.

The researchers were interested in finding an application where a single brain scan could provide information about the individual. They chose to assess the maturity of the brain, and used chronological age as a reference measure. Instead of using regular fMRI, the researchers used an even fancier version, fcMRI (fc stands for “functional connectivity”). This type of imaging measures the spontaneous activity between brain regions. How strongly different brain regions interact with each other is thought to be shaped by all the experiences one accumulates over time, hence the potential to determine maturity from these kinds of measures.

Participants aged seven to 30 years old were asked to undergo a five-minute brain scan. What followed was an extremely complex series of models and algorithms developed by the researchers to establish a “maturation curve”, from which they could then predict the maturity of a given brain based on where its scan fits along the curve.

Ultimately, it was established that yes, a single scan can provide information about the person’s brain: it can predict its maturity level. But couldn’t we already determine brain age just by looking at its shape? For the most part, yes. The reason this article is relevant is because quite a few brain diseases and disorders don’t have a signature shape (unlike tumors, for example, which can sometimes be spotted on a static image). Therefore, having a tool that allows us to assess brain function without having to compare large groups could become very valuable in the diagnosis of some brain disorders (provided we first determine the functional signature of these disorders).

As an interesting side note, the researchers' results suggest that on average, functional brain maturity levels out at about age 22. This obviously represents a physiological maturity level, not a cognitive maturity level, thank goodness. When I was 22, I used to think I knew everything. How I've "matured" since then!Reference: Prediction of individual brain maturity using fMRI. Dosenbach N.U.F. et al. Science 329:1358-61 (2010).

Wednesday, September 8, 2010

When you walk into any baby store, it quickly becomes obvious that boys like blue trucks and girls like pink dolls. You might find a yellow pajama with a puppy on it, but that one is probably intended for the pregnant mom who doesn’t want to find out the sex of her baby but wants to buy a pajama. Many researchers have speculated on why boys and girls like different colors and different toys. There are three main theories out there. The first one, the “social learning” theory, suggests that children like certain toys and colors because they are socialized to like them: they like the toys their parents buy for them. The second theory, the “cognitive theory”, suggests that a child knows what gender he or she is, and is aware of the stereotypes, so he or she chooses accordingly. Finally, the “hormonal theory” suggests that sex differences in the prenatal hormone environment changes how the brain organizes itself and leads to female- or male-typed behaviours. For example, high levels of androgen (the male hormone) lead to brain masculinization and the choosing of trucks over dolls. While this may sound crazy, experiments have shown that female fetuses exposed to abnormally high androgen concentrations spend more time playing with masculine toys compared to regular girls. To make things even more complicated, studies have shown that some kinds of monkeys also show sex-specific toy preferences (and Daddy Monkey doesn’t shop at Wal-Mart, so there goes the “social learning” theory). So, is it already in your brain when you’re born, or do you learn to love blue trucks or pink dolls?

Researchers set out to shed some light on this question by studying 120 boys and girls aged 12 to 24 months. The task was very simple: the child was shown two images simultaneously (for example, a red car and a red doll, or a blue car and a pink car), and a camera recorded how long the child looked at each image, which is a measure of interest.

The researchers found that boys preferred cars and girls preferred dolls. No big surprise there. Unfortunately, because children 12 months old or older have already been provided with sex-typed toys, their looking preference may reflect the types of toys they have at home and the researchers could not draw any conclusions on whether this behavior was learned or innate.

The interesting finding lies in the colors: as it turns out, the children cared very little about the color of the images. Boys preferred the cars, regardless of whether they were pink or blue, and conversely, girls preferred the dolls, regardless of their color. In fact, the researchers found that as a whole, everybody liked red the most. This finding indicates that the stereotypical color preferences seen in older children are most likely learned behaviours.

As I’ve mentioned before, my favorite kind of research article is the one that leaves me with more questions than I started with, and this is one of them. Why was pink adopted as the “girl” color if girls aren’t naturally drawn to it? At what stage does the shift occur from not caring about colors to caring about them? Is this shift really purely socially driven? In any case, the next pajama I buy for a child will be red.

About Me

Dr. Julie is an Assistant Professor of Neurology at the National Core for Neuroethics and the Djavad Mowafaghian Centre for Brain Health at the University of British Columbia. She holds a PhD in Neuroscience.